The working voltage is the main basis, and of course there are insulation level material groups. Generally testing and measured the power climbing distance and the electrical gap are not only the power part. As long as the electric part is passed, it needs to be measured.  
 
Such a small voltage does not need to test the climbing distance and electrical gap.  
The working voltage is the main basis, and of course there are insulation level material groups.  
Generally testing and measured the power climbing distance and the electrical gap are not only the power part. As long as the electric part is passed, it needs to be measured.  
 
The electrical gap is directly related to the climbing distance and the voltage, and the opposite relationship between them. The requirements for them are not all circuits, but they are not clear between naked adjacent conductors. The standards to the scope below the safety voltage are not clear.